Phoenixin peptide in goldfish promotes feeding as a feedforward signal — eating triggers PNX expression which stimulates more food intake.
FeedforwardFeeding itself increases phoenixin expression which stimulates further food intake — a positive feedback loop
What the researchers found
Phoenixin acts as a feedforward appetite signal in goldfish — feeding increases PNX expression, which in turn stimulates additional food intake.
Why it matters
Understanding feedforward appetite signals may explain binge eating mechanisms and could identify new targets for appetite control.
The numbers in context
Two PNX isoforms and one GPR173 cloned; both IP and ICV injection of PNX20a/b increased food intake; expression rose after feeding, fell with fasting.
How the study worked
Gene cloning, tissue expression (RT-PCR), phylogenetic analysis, in silico modeling, and feeding experiments in goldfish.
Who was studied
Goldfish
What this study cannot tell us
Fish model — feedforward mechanisms may differ in mammals. Single species studied.
How to read the evidence
Fish model study with comprehensive molecular characterization — novel mechanistic finding but needs mammalian confirmation.
When this study was published
Published in 2025, characterizing phoenixin's role in appetite for the first time in fish.
The bigger picture
Phoenixin adds to the growing list of appetite-regulating peptides, with a unique feedforward mechanism distinct from hunger/satiety hormones.
Questions still open
- Does phoenixin play a similar feedforward role in human appetite?
- Could blocking phoenixin help prevent binge eating?
Common questions
What is phoenixin?
Why study appetite in fish?
Read the original research
Goldfish phoenixin: (I) structural characterization, tissue distribution, and novel function as a feedforward signal for feeding-induced food intake in fish model.
Frontiers in endocrinology, 16, 1570716
Citation
Qin, Xiangfeng; Ye, Cheng; Chan, Ying Wai; Wong, Anderson O L. (2025). Goldfish phoenixin: (I) structural characterization, tissue distribution, and novel function as a feedforward signal for feeding-induced food intake in fish model.. Frontiers in endocrinology, 16, 1570716. https://doi.org/10.3389/fendo.2025.1570716